Basic C Language MCQs

1. Which of the following is a correct comment in C?

• a) # This is a comment
• b) // This is a comment
• c) <!-- This is a comment -->
• d) <comment >This is a comment </comment >

2. Which data type is used to create a variable that should store text?

• a) char
• b) string
• c) text
• d) int

3. Which of the following is the correct syntax to declare a variable in C?

• a) int number;
• b) integer number;
• c) num number;
• d) var number;

4. Which of the following is used to print a message on the screen in C?

• a) printf();
• b) print();
• c) echo();
• d) output();

5. Which of the following is the correct way to read a string input from the user in C?

• a) scanf("%s ", &str);
• b) input("%s ", &str);
• c) get("%s ", &str);
• d) read("%s ", &str);

6. Which function is used to find the length of a string in C?

• a) strlen()
• b) length()
• c) strlength()
• d) strsize()

7. What is the index of the first element in an array in C?

• a) 0
• b) 1
• c) -1
• d) None of the above

8. Which of the following is a loop construct in C?

• a) for
• b) while
• c) do-while
• d) All of the above

9. How do you declare a constant in C?

• a) #define PI 3.14
• b) const float PI = 3.14;
• c) constant PI = 3.14;
• d) Both a and b

10. Which of the following is a relational operator in C?

• a) ==
• b) =
• c) ++
• d) --

11. What is the correct syntax for a for loop in C?

• a) for(initialization; condition; increment)
• b) for(condition; initialization; increment)
• c) for(initialization, condition, increment)
• d) for(initialize; condition; increment)

12. What is the output of the following code? printf("%d ", 10 >9);

• a) 1
• b) 0
• c) 10
• d) 9

13. Which keyword is used to return a value from a function?

• a) return
• b) exit
• c) end
• d) close

14. What is the size of an int data type in C (in bytes)?

• a) 2
• b) 4
• c) 8
• d) It depends on the compiler

15. Which of the following is a correct way to declare a pointer in C?

• a) int *ptr;
• b) int ptr*;
• c) int * ptr;
• d) *int ptr;

16. Which operator is used to access the value at the address stored in a pointer variable?

• a) *
• b) &
• c) %
• d) @

17. Which function is used to allocate memory dynamically in C?

• a) malloc()
• b) alloc()
• c) dynamicalloc()
• d) memalloc()

18. What will be the output of the following code? printf("%d ", 5/2);

• a) 2
• b) 2.5
• c) 3
• d) 0

19. Which of the following is the correct syntax to declare a structure in C?

• a) struct { int a; float b; } myStruct;
• b) structure { int a; float b; } myStruct;
• c) struct { int a; float b; } myStruct()
• d) structure { int a; float b; } myStruct()

20. Which of the following is a valid array declaration in C?

• a) int arr[10];
• b) array int arr[10];
• c) int arr[10];
• d) int[10] arr;

21. Which of the following function is used to open a file in C?

• a) open()
• b) fopen()
• c) fileopen()
• d) openfile()

22. What is the correct way to check for the end of a file in C?

• a) feof(file_pointer)
• b) endfile(file_pointer)
• c) fileend(file_pointer)
• d) eof(file_pointer)

23. What will be the output of the following code? int x = 5; printf("%d ", x++);

• a) 5
• b) 6
• c) 4
• d) 0

24. Which function is used to compare two strings in C?

• a) strcmp()
• b) compare()
• c) strcompare()
• d) strcomp()

25. Which of the following is not a storage class in C?

• a) auto
• b) register
• c) static
• d) public

26. Which of the following is used to define a macro in C?

• a) #define
• b) define
• c) macro
• d) #macro

27. What will be the output of the following code? printf("%c ", 'A '+ 1);

• a) B
• b) A
• c) C
• d) D

28. Which of the following is a valid declaration of a function in C?

• a) int func();
• b) function int func();
• c) int func;
• d) func() int;

29. What does the continue  statement do in a loop?

• a) Skips the current iteration and continues with the next iteration
• b) Terminates the loop
• c) Returns control to the start of the loop
• d) None of the above

30. Which of the following is a valid syntax for an if statement in C?

• a) if(condition) { statements; }
• b) if(condition) statements;
• c) if { condition } statements;
• d) if(condition) { statements }

31. What will be the output of the following code? printf("%d ", 10 % 3);

• a) 1
• b) 3
• c) 0
• d) 10

32. Which of the following is used to terminate a statement in C?

• a) Semicolon (;)
• b) Colon (:)
• c) Dot (.)
• d) Comma (,)

33. Which of the following is the correct way to initialize an array in C?

• a) int arr[3] = {1, 2, 3};
• b) int arr[3] = [1, 2, 3];
• c) int arr[] = {1, 2, 3};
• d) int arr = {1, 2, 3};

34. Which of the following is not a bitwise operator in C?

• a) &
• b) |
• c) ^
• d) &&

35. Which of the following is used to declare an array of pointers in C?

• a) int *arr[10];
• b) int arr[10];
• c) int arr*;
• d) int *arr;

36. What is the output of the following code? printf("%d ", 5 &3);

• a) 1
• b) 3
• c) 5
• d) 0

37. Which header file is required for using the malloc  function?

• a) stdlib.h
• b) stdio.h
• c) malloc.h
• d) string.h

38. What is the return type of the malloc  function?

• a) void*
• b) int*
• c) char*
• d) float*

39. What is the purpose of the free  function in C?

• a) To deallocate memory previously allocated by malloc  or calloc
• b) To allocate memory
• c) To free up a file
• d) To clear the screen

40. Which of the following functions is used to write a character to the standard output in C?

• a) putchar()
• b) getchar()
• c) getch()
• d) write()

41. Which of the following function signatures is correct for main in C?

• a) int main(void)
• b) int main()
• c) void main()
• d) All of the above

42. Which of the following is the correct way to define a symbolic constant in C?

• a) #define PI 3.14
• b) const PI = 3.14;
• c) define PI 3.14
• d) PI = 3.14;

43. Which of the following is a correct way to declare a multi-dimensional array in C?

• a) int arr[3][4];
• b) int arr[4][3];
• c) int arr[3,4];
• d) int arr[4,3];

44. Which of the following functions is used to copy a string in C?

• a) strcpy()
• b) strncpy()
• c) memcpy()
• d) strcat()

45. What is the output of the following code? printf("%d ", sizeof(int));

• a) 2
• b) 4
• c) 8
• d) Depends on the compiler

46. Which of the following is not a valid variable name in C?

• a) _var
• b) var1
• c) 1var
• d) var_1

47. What will be the output of the following code? printf("%d ", 1 <<2);

• a) 4
• b) 2
• c) 1
• d) 8

48. Which of the following is a preprocessor directive in C?

• a) #include
• b) include
• c) #include <stdio.h >
• d) None of the above

49. Which of the following is used to skip to the next line in a file in C?

• a) \n
• b) \t
• c) \r
• d) \b

50. What is the output of the following code? printf("%d ", 2 == 2.0);

• a) 1
• b) 0
• c) 2
• d) None of the above